Localized-IBL implementation

[Chosker]

@Starkium

All the materials error out for me so I don’t think it works in forward. There are material nodes/functions being used that are not available in forward. I’d really appreciate it if you could look at that and see if you can do anything about this as forward render SORELY needs this project.

I’ll take a look when I do the 4.25 port.
do you have an example of a material that error out (and the error itself), or is it everything?